在本研究中，將利用醋酸纖維（Cellulose acetate，CA） 和三醋酸纖維（Cellulose triacetate，CTA）作為聚合材研發一正滲透膜，並黏合上聚對苯二甲酸乙二酯不織布網膜以增加其效能。在製膜階段，為了解各製作條件對薄膜結構和運作效能的影響，我們將測試薄膜CTA/CA比、CTA/CA聚合材濃度、PET膜的有無和淬膜時間並最佳化之。製作的薄膜下一步將會被應用到截流式和掃流式薄膜系統並以水通量、鹽反滲透通量和比鹽反滲透通量作為評估係數。這些薄膜也將被測試於兩個方向：在FO mode中，緻密層將面對進流液。反之，在PRO mode中，緻密層將面對驅動液。在掃流式系統中，將進一步測試掃流流速和阻塞情形來增進薄膜效益。SEM和接觸角分析揭露本研究薄膜擁有典型的不對稱型態且PET膜如同三明治般良好的嵌入薄膜中；且由於CA/CTA聚膜材的親水性使得水通量得以提升。實驗結果顯示薄膜於CA/CTA比1:3時，薄膜溶液濃度16%有最佳的效能，水通量達23.88L/m2h，鹽反滲透量僅13.62g/m2h，比鹽反滲透通量僅0.57g/L，顯示其有極佳的選擇性。本研究利用1M 氯化鈉溶液作為驅動液和DI 水作為進流液，薄膜運作於掃流流量520mL/min，掃流方向為逆流的掃流系統。另外。PRO mode於阻塞後產生的阻力將大於FO mode。 In this research, the forward osmosis membrane was produced by using cellulose triacetate (CTA) and cellulose acetate (CA) with polyethylene terephthalate (PET) nonwoven mesh to enhance membrane performance. The preparation conditions including CTA/CA ratio, CTA/CA concentration, casting with/without PET and annealing time were tested for their effects on formation and performance of membranes. The performance of produced membranes was carried out with two filtration systems with dead-end and cross-flow which were employed for the investigation of the water flux, reverse salt flux and specific reverse salt flux. These membranes were tested under two orientations; in the FO mode, the active layer was oriented toward the feed solution whereas, in the PRO mode, the active layer was oriented toward the draw solution. For cross-flow filtration, the operating conditions including flow pattern flow rate and fouling of optimized membrane were studied. SEM and water contact angle analyses showed the CTA/CA membrane has a typical asymmetric three-layered sandwich structure and nonwoven PET was well embedded in the membrane, and the CTA/CA membranes have hydrophilic properties to allow water to penetrate the pore which reflects better water permeation. The result indicated that the optimized membrane with CTA/CA ratio 1:3 under the concentration of CTA/CA 16wt.% has the available water flux and reverse salt flux in cross-flow filtration of 23.88 L/m2.h and 13.62 g/m2.h, respectively. In addition, the membrane was high selectivity properties with the relatively minimal specific reverse salt flux of 0.57 g/L. The performance of the optimal membrane was tested using 1M NaCl draw solution and DI water as the feed solution which both side along with flow rate 520 mL/min in a counter-current pattern. Moreover, the total resistance of the membrane in the PRO mode higher than that in the FO mode.
